Why Reward Terrorism?

Here is the best way that I have heard to date on how to explain to people why rewarding terrorism is counterproductive. People with children will understand this perfectly.

Suppose you have two children, each of whom has an equally legitimate grievance. One of them discusses it rationally with you, while the other one hits you over the head with a stick. The latter will surely get your attention, but only a terrible parent would give preference to the grievance of the violent child over the peaceful one. To do that would be encouraging more violence by both children.

Does that make any sense, sounds logical to me? So why is this such a hard principal to follow for most of the world? Appeasing terrorism only leads to more terrorism, simply as that.